The SBI DBCN extension needs to be emulated in user-space so let
us forward console_puts() call to user-space.
Signed-off-by: Anup Patel <apatel@xxxxxxxxxxxxxxxx>
---
arch/riscv/include/asm/kvm_vcpu_sbi.h | 1 +
arch/riscv/include/uapi/asm/kvm.h | 1 +
arch/riscv/kvm/vcpu_sbi.c | 4 ++++
arch/riscv/kvm/vcpu_sbi_replace.c | 31 +++++++++++++++++++++++++++
4 files changed, 37 insertions(+)
diff --git a/arch/riscv/include/asm/kvm_vcpu_sbi.h b/arch/riscv/include/asm/kvm_vcpu_sbi.h
index 8d6d4dce8a5e..a85f95eb6e85 100644
--- a/arch/riscv/include/asm/kvm_vcpu_sbi.h
+++ b/arch/riscv/include/asm/kvm_vcpu_sbi.h
@@ -69,6 +69,7 @@ extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_ipi;
extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_rfence;
extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_srst;
extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_hsm;
+extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_dbcn;
extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_experimental;
extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_vendor;
diff --git a/arch/riscv/include/uapi/asm/kvm.h b/arch/riscv/include/uapi/asm/kvm.h
index 917d8cc2489e..60d3b21dead7 100644
--- a/arch/riscv/include/uapi/asm/kvm.h
+++ b/arch/riscv/include/uapi/asm/kvm.h
@@ -156,6 +156,7 @@ enum KVM_RISCV_SBI_EXT_ID {
KVM_RISCV_SBI_EXT_PMU,
KVM_RISCV_SBI_EXT_EXPERIMENTAL,
KVM_RISCV_SBI_EXT_VENDOR,
+ KVM_RISCV_SBI_EXT_DBCN,
KVM_RISCV_SBI_EXT_MAX,
};
diff --git a/arch/riscv/kvm/vcpu_sbi.c b/arch/riscv/kvm/vcpu_sbi.c
index 9cd97091c723..b54fe52c915a 100644
--- a/arch/riscv/kvm/vcpu_sbi.c
+++ b/arch/riscv/kvm/vcpu_sbi.c
@@ -66,6 +66,10 @@ static const struct kvm_riscv_sbi_extension_entry sbi_ext[] = {
.ext_idx = KVM_RISCV_SBI_EXT_PMU,
.ext_ptr = &vcpu_sbi_ext_pmu,
},
+ {
+ .ext_idx = KVM_RISCV_SBI_EXT_DBCN,
+ .ext_ptr = &vcpu_sbi_ext_dbcn,
+ },
{
.ext_idx = KVM_RISCV_SBI_EXT_EXPERIMENTAL,
.ext_ptr = &vcpu_sbi_ext_experimental,
diff --git a/arch/riscv/kvm/vcpu_sbi_replace.c b/arch/riscv/kvm/vcpu_sbi_replace.c
index 7c4d5d38a339..347c5856347e 100644
--- a/arch/riscv/kvm/vcpu_sbi_replace.c
+++ b/arch/riscv/kvm/vcpu_sbi_replace.c
@@ -175,3 +175,34 @@ const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_srst = {
.extid_end = SBI_EXT_SRST,
.handler = kvm_sbi_ext_srst_handler,
};
+
+static int kvm_sbi_ext_dbcn_handler(struct kvm_vcpu *vcpu,
+ struct kvm_run *run,
+ struct kvm_vcpu_sbi_return *retdata)
+{
+ struct kvm_cpu_context *cp = &vcpu->arch.guest_context;
+ unsigned long funcid = cp->a6;
+
+ switch (funcid) {
+ case SBI_EXT_DBCN_CONSOLE_WRITE:
+ case SBI_EXT_DBCN_CONSOLE_READ:
+ case SBI_EXT_DBCN_CONSOLE_WRITE_BYTE:
+ /*
+ * The SBI debug console functions are unconditionally
+ * forwarded to the userspace.
+ */
+ kvm_riscv_vcpu_sbi_forward(vcpu, run);
+ retdata->uexit = true;
+ break;
+ default:
+ retdata->err_val = SBI_ERR_NOT_SUPPORTED;
+ }
+
+ return 0;
+}
+
+const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_dbcn = {
+ .extid_start = SBI_EXT_DBCN,
+ .extid_end = SBI_EXT_DBCN,
+ .handler = kvm_sbi_ext_dbcn_handler,
+};
--
2.34.1
